The game logs into HORIZON_HOME and falls back to the player's own game folder when it is unset. Harnesses
that set only HORIZON_NO_AUDIO (and test_native_client, which set nothing) wrote logs, and on a world run
advancements, into ~/Library/Application Support/horizon.
lab.game_env gives every game a fresh HORIZON_HOME, HORIZON_LAUNCHER_HOME, XDG_DATA_HOME and XDG_CONFIG_HOME,
no audio and no launcher self-update; a folder the caller passes is kept. Every launcher of the game uses it,
parity.py gives each harness its own HORIZON_HOME, and tests/test_game_home.py fails for a script in tools/
that starts the game without it.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Settings gets an AI group with the No AI switch (horizon_core::no_ai, the
same switch the game reads) and, while it is off, a Connect an AI agent
section that replaces the old command-line note: a picker for Claude Code,
Codex, Cursor or any MCP client, the ready-made config with a Copy button,
the client's own add command (claude mcp add / codex mcp add) shown and run
only when the player clicks Add, and Test the connection, which starts the
MCP server as a client would and says how many tools answered. Client CLIs
are found on the PATH or in the folders installers use, since a launcher
started from the desktop gets a short PATH on macOS.
horizon-launcher agent-config --test runs the same test; the launcher
harness checks it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The MCP tools are generated from the CLI's clap definition (cli_tools.rs):
mods_search is horizon-launcher mods search, with the same arguments, and
a call runs that command with --json. So the mod browser, modpacks, hosted
servers, settings, game arguments, data collection, desktop entry and the
benchmark are all reachable, and new CLI commands become tools by
themselves. Destructive ones need confirm: true and carry destructiveHint.
The session keeps play, server (with server_command/log/stop),
account_list and account_sign_in in-process, renamed after the CLI
(launch_client is play; play takes join for an invite code).
New CLI commands: settings [KEY VALUE] (selected version, folders,
install-new-versions, opening animation) and agent-config, the MCP config
for Claude Code, Codex, Cursor and any client. play takes --world and
--creative. Under No AI, mcp and agent-config are hidden and refused.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
horizon_core::no_ai reads and writes the noAi line of the game's
horizon-extras.txt, so the launcher and the game share one switch. While
it is on the game never opens its control socket, horizon-ctl refuses every
command with exit 4 and kind denied, horizon-ctl mcp and horizon-launcher
mcp refuse to start (and refuse calls if it is turned on mid-session), and
horizon-launcher no-ai [on|off] shows or sets it. The game's extras keep
the key when they rewrite the file. Both e2e harnesses check it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- DEFAULT_ENDPOINT is https://telemetry.playhorizon.dev. The heartbeat, the launcher's live count and the
outbox upload all go there; HORIZON_TELEMETRY_URL still names another server, and HORIZON_TELEMETRY_URL=off
sends nothing at all. CI workflows and the harnesses that start the game or the launcher set off. Consent
is unchanged: the four switches stay opt-in, only the anonymous ping is always on.
- GET /v1/benchmarks/summary: players' benchmark uploads grouped by GPU, CPU, render distance and game, groups
of 3+ installs only, medians per install then across installs, no install ID, day, OS version, driver,
memory or screen. Cached 10 minutes, CORS for the website. Same rules as website/scripts/benchmarks.mjs,
tested on the same fixtures; a deleted install leaves its groups at once.
- /v1/aggregate no longer lists the newest 50 raw benchmark reports (hardware, driver, day, one install each):
uploads are published only through the summary.
- Behind Railway's proxy the rate limit counts X-Real-IP, else the last X-Forwarded-For entry (the one the
proxy adds; a client could choose the first). Still in memory only, never stored or logged.
- crates/horizon-telemetry-server/railway.json: Dockerfile build from the repository root, health check
/healthz, one replica in europe-west4 (one SQLite file on the /data volume).
- Docs: docs/telemetry.md, the server README (the summary's shape, Railway setup), the privacy page (the ping
is on, where the data lives, how benchmark uploads are shown).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
lab.VERSION, lab.GAME (.local/minecraft/<version>) and lab.RESOURCES
(.local/horizon-client/<version>) come from the lock, and lab.version_info()
reads the pinned client jar's version.json. Every harness, generator and
tool that named 26.3 (resource folders, jar and source paths, result
records, the vanilla client's --version and asset index, the bare login
client's protocol, the benchmark's options.txt data version, the packet id
table's header) uses them, so a candidate worktree pinned to another version
runs them unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
An agent now needs one MCP server. horizon-launcher mcp runs the selected
version's horizon-ctl mcp as a child and offers its tools as game_<name>
(all but launch, which launch_client covers), passing calls and image
results through. launch_client starts the game with a control socket in
the launcher's data folder, takes world, creative and offscreen, and
returns once the socket answers. A game tool called while no game listens
says to call launch_client.
tools/launcher_mcp_e2e.py checks it end to end against this checkout's
builds in a scratch launcher home.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Ludovic Marie